The invention relates to the inductive charging of a rechargeable battery of a vehicle. In particular, the invention relates to a method and to a corresponding device for securing a primary coil used in the inductive charging.
Vehicles, in particular vehicles with an electric drive, include rechargeable batteries for storing electrical energy. The rechargeable battery of a vehicle can be recharged, for example, by connection to a power source external to the vehicle (for example by connection to a public electrical grid). One approach to the automatic, cableless, inductive charging of the battery of the vehicle consists in the electrical energy being transmitted to the battery from the floor to the underbody of the vehicle by magnetic induction via the underbody clearance. This is illustrated by way of example in FIG. 1. In particular, FIG. 1 shows a vehicle 100 with an accumulator 103 for electrical energy (for example with a rechargeable battery 103). The vehicle 100 includes a “secondary coil” 102 in the vehicle underbody, wherein the secondary coil 102 is connected to the accumulator 103 via impedance matching (not shown) and a rectifier 101.
The secondary coil 102 can be positioned over a primary coil 111, wherein the primary coil 111 is attached, for example, to the floor of a garage. The primary coil 111 is connected to a power supply 110. The power supply 110 may have a radio frequency generator which generates an alternating current (AC) in the primary coil 111, as a result of which a magnetic field is induced. In the event of sufficient magnetic coupling between primary coil 111 and secondary coil 102 via the underbody clearance 120, a corresponding voltage and, therefore, also a current is induced in the secondary coil 102 by the magnetic field. The current induced in the secondary coil 102 is rectified by the rectifier 101 and stored in the accumulator 103 (for example in the battery). Electrical energy can thus be transmitted in a cableless manner from the power supply 110 to the energy accumulator 103 of the vehicle 100.
In order to achieve sufficient magnetic coupling between primary coil 111 and secondary coil 102, the secondary coil 102 of the vehicle 100 should be positioned with a certain precision (typically ±10 cm) over the primary coil 111 (which is also referred to as a floor unit). In order to ensure precise positioning, the primary coil 111 should be secured fixedly on the floor in order to avoid slipping or movement of the primary coil 111. However, permanent securing, for example using a screw connection of the primary coil 111 to the floor, is frequently not possible here. For example, in an underground garage which is accessible to a large number of unknown individuals, it may not be permitted to carry out a fixed installation of the primary coil 111 in the floor (for example by means of screws). Furthermore, it may not be possible for any permanent holes for the screws of a primary coil 111 to be drilled on a parking space which is used only temporarily. In addition, it may not be possible for any holes to be drilled, for example, in a garage with a high-quality floor covering. Furthermore, it is conceivable that the primary coil 111 will have to be transferred in the foreseeable future to a different location, and therefore an installation of the primary coil 111 that can be removed without any problems or residue is desired.
In order to secure the primary coil 111, use could be made of a slip-proof mat. Such a slip-proof mat can be removed without a residue. However, a slip-proof mat does not provide adequate theft protection for the primary coil 111. A slip-proof mat therefore cannot be used in publicly accessible regions (such as, for example, in an underground garage).
The present document describes a method and a device which permit a primary coil 111 to be secured on a floor in a theft-proof manner and so as to be removable without a residue.
According to one aspect, a device is provided for securing a rail on an underlying surface (for example on the floor of a garage or a parking space). The device can be used in particular for placing a primary coil on the underlying surface. The rail can be a metal rail. The rail has a lower wall and at least one side wall. For example, the rail can have a rectangular cross section. Furthermore, the rail can have an elongated extent and can form a length-extended cuboid. The rail can form a frame by which a space for receiving the primary coil is formed. Alternatively, the rail can have a cavity, for example for receiving a cable.
The device has a connecting tape (for example an adhesive tape or a touch-and-close tape) which has a longitudinal extent along the rail. The connecting tape can in particular have a length which corresponds to the length of the rail. Furthermore, the connecting tape has a sufficient width in order to cover the lower wall and to at least partially (but optionally also completely) cover the at least one side wall of the rail. The rail typically comprises two side walls, and the connecting tape typically has a width in order to at least partially (but optionally also completely) cover the two side walls and the entire lower wall.
The connecting tape typically has a leaf-shaped configuration. Furthermore, the connecting tape typically has longitudinal sides along the longitudinal extent of the rail and ends along the cross section of the rail. Furthermore, the connecting tape has an outer side and an inner side. The inner side is designed here to enter laterally into connection with the rail, and the lower outer side is designed to enter into connection with the underlying surface.
The connecting tape has, on the outer side of the connecting tape, an external connecting layer which is designed to produce adhesion along the lower wall of the rail between the connecting tape and the underlying surface. The external connecting layer can be designed in particular to produce an adhesive connection and/or a touch-and-close connection. The adhesion between the connecting tape and the underlying surface can be designed in particular in such a manner that release of the rail in the transverse direction with respect to the underlying surface is prevented.
Furthermore, the connecting tape has, on the inner side, at least one internal connecting layer which is designed to produce adhesion along the at least one side wall of the rail between the at least one side wall of the rail and the connecting tape. The internal connecting layer can be designed in particular to produce an adhesive connection and/or a touch-and-close connection. The adhesion between the at least one side wall of the rail and the connecting tape can be designed in particular in such a manner that release of the rail in a direction perpendicular to the underlying surface is prevented.
The adhesions (or adhesive connections) are typically configured in such a manner that they can be removed without residue when required.
The device furthermore has a housing which is connectable to the rail and blocks access to the rail when the housing is connected to the rail. The housing can be designed to surround and/or to cover a primary coil for inductively charging a vehicle. Alternatively or additionally, the housing can be designed to enclose a cable for connecting the primary coil to a power supply. The housing therefore prevents unauthorized release of the adhesions and therefore a possible theft of a primary coil enclosed by the rail or a cable enclosed by the rail.
The rail and the housing can be connected to each other by a screw connection, for example. The housing can have a closeable covering by which access to the screw connection can be prevented in a closed state. By opening the cover, installation of the housing on the rail can be made possible. Furthermore, unauthorized removal of the housing can be prevented by a closed covering.
The connecting tape can have, on the inner side, an internal region for receiving the lower wall of the rail. The internal region typically lies opposite the extemal connecting layer. The internal region cannot have any adhesive connecting layer. This is advantageous with respect to removal of the rail. In a corresponding manner, the connecting tape can have, on the outer side, an external region which lies opposite the at least one internal connecting layer and which likewise does not have an adhesive connecting layer. This is advantageous for the handling of the connecting tape since a connecting layer in the external region would get in the way during the installation and removal of the rail.
The connecting tape can have a multiplicity of segments along the longitudinal extent. Internal connecting layers between two adjacent segments of the multiplicity of segments can be interrupted. In other words, the internal connecting layers and/or the connecting tape can be divided in the regions which are intended to cover the at least one side wall of the rail into separate segments. This has the advantage that the individual segments have a reduced adhesion force which can be overcome by a person in order to release an individual segment from the side wall of the rail. The connecting tape can therefore be released from the rail segment-by-segment. Furthermore, the multiplicity of segments together have a large adhesion force which prevents release of the rail. The division into segments also permits installation on underlying surfaces which are not entirely flat.
The connecting tape can have one or more tabs on a longitudinal side for detaching the adhesion between the at least one side wall of the rail and the connecting tape. In particular, each segment of the multiplicity of segments can have a tab. Alternatively or additionally, the connecting tape can have a tab at one end for detaching the adhesion between the connecting tape and the underlying surface. Pulling off the connecting tape can be facilitated by way of a tab.
Furthermore, the connecting tape can have transverse reinforcements in the region for receiving the lower wall of the rail in order to make it difficult to detach the adhesion between the connecting tape and the underlying surface by means of forces acting transversely on the rail.
Furthermore, a method for securing a rail on an underlying surface is described. The method includes features which correspond to the features of the device.
It should be noted that the methods, devices and systems described in this document can be used either on their own or in combination with other methods, devices and systems described in this document. Furthermore, any aspects of the methods, device and systems described in this document can be combined with one another in diverse ways. In particular, the features of the claims can be combined with one another in diverse ways.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.